AIRWAYS IN SPECIAL CONDITIONS Flashcards
what is the prevalence of obesity in the US?
36% of adults
what is the best method for bringing an obese pt into the correct sniff position?
elevate trunk and head with sheets or ramp
what is the primary concern of airway management when attempting to intubate an obese patient?
obese patients desaturate quickly due to decreased FRC (oxygen reserve)
what is the component of the obese airway that presents the biggest problem in visualization of the vocal cords?
paraglottic soft tissue
what is the overall obstetric mortality rate?
1:20,000
what is the anesthesia-related obstetric mortality rate?
1:500,000
what is the leading cause of anesthetic mortality?
airway management
what are the risk factors of pregnancy and airway management?
failure to intubate
aspiration
hypoxemia
urgency for two patients
failure to prepare completely
what are the aspiration risks for pregnant women?
solid and or liquid ingestion soon before delivery
decreased gastric emptying
increased gastric acidity
what factors decrease gastric emptying in gravid women?
progesterone
stress of labor
narcotics
what factors predispose gravid women to decreased gastro-esophageal sphincter tone and aspiration?
reflux
anticholinergics
narcotics
insertion/removal of NG tube
what percent of obstetric anesthia-related aspiration is due to hiatial hernia?
27%
how much is gastric pressure increased in mothers pregnant with a single child?
7 → 17cmH2O
how much is gastric pressure increased in mothers pregnant with twins?
7 → 40cmH2O
how much does lithotomy postioning increase gastric pressure increased in gravid mothers?
17 → 40cmH2O
what are the contributing factors that increase the likelihood of a failed intubation in gravid pts?
upper airway edema
adiposity of head, neck, trunk
breast enlargement
by what margin does pregnancy increase the incidence of failed intubations?
increased 10 fold
nongravid – 1:2500
gravid – 1:250
what are the contributing factors that increases the risk of hypoxemia in gravid pts?
20% decrease in FRC
VO2 increase
how does VO2 vary in gravid term vs. active labor pts?
20% increase VO2 – term
60% increase VO2 – active labor
what four steps must you take to manage increased airway risks of gravid pts?
identify risks
prevent acid reflux
identify number of fetuses
vigilance during active labor
what position should the gravid pt be in while evaluating the airway?
supine
what physical characteristics of the gravid pt should be assessed during evaluation of the potentially difficult airway?
head, neck, trunk, breasts
what is the established patient preparation protocol for labor?
- NPO – provide good hydration
- cimetidine (tagamet) 300mg IV – 60min prior (histamine receptor antagonist; inhibits stomach acid production)
- metoclopramide (reglan) 10mg IV – 30min prior (anti-nauseau and gut-motility inhibitor)
- sodium citrate 30ml PO – immediately prior (used as an antacid)
outline plan A for orotracheal intubation of the gravid pt
goal: prepare for 1st attempt success
optimize pt position
provide complete preoxygenation
down size ETT
utilize sellick maneuver throughout
use ETT introducer if needed
what is the goal of Plan B when attempting to intubate the gravid pt?
oxygenate/support both pts
what should be applied continuously from Plan A to Plan B airway management of the gravid pt?
sellick maneuver
what is the goal of Plan C airway management of the gravid pt?
establish viable airway with oxygenation
what two methods of airway management are viable for Plan C airway management of the gravid pt?
HPOV or RGW
what three structures should be evaluated for arthritis in the geriatic airway?
the cervical spine, the cricoarytenoid joint, and the temporomandibular joint
what changes in the chest wall and lungs of the geriatric pt may present difficulty for airway management?
muscle loss, stiffer chest wall
decreased lung elastic recoil
decreased vital capacity
despite the comorbidities of the geriatric chest wall and lungs, what component of total lung capacity remains unaffected?
FRC
how might arthritis in the cervical spine impact DL/intubation?
limited ROM – little to no atlanto-occipital extension
how might arthritis of the TMJ impact DL/intubation?
limited mouth opening – have alternate plan for intubation
how might arthritis of the cricoarytenoid joint impact the geriatric airway?
hoarseness (needs to be documented) – may limit the ability of the vocal cords to relax
how might changes in the chest wall and lungs impact airway management of the geriatric pt?
decreased ability to cough and protect airway – be cautious during emergence; pt must be able to cough and protect airway
how might dentition of the geriatric pt (endentulous, facial skin looseness) affect airway management?
increased difficulty in mask fit/ PPV – use adjuncts (OAW, face mask strap)
what risk does the pt with osteoporosis present?
increased fracture risk
how might the reliability and cooperation of a senile pt affect airway evaluation and management?
poor historian – use alternate source for history
increased safety risk – minimum to no sedation
when drainage in the neck is compromised, how is airway patency affected?
edema in the glottic tissues decrease vocal cord visualization leading to increased risk of intubation failure
definition: supine, head lower than heart, legs and pelvis elevated
trendelenburg position
the trendelenburg postition was first described by whom?
Dr. Willy Meyer (1885)
credited to his teacher, Friedrich Trendelenburg, used for urologic surgery in 1870
when was the trendelenburg position first used in the US?
1890
what advantages does tburg give for surgical procedures?
physical access to specific regions
moves abdominal contents cephalad
alters regional circulation
how does tburg negatively affect anesthetic procedures?
increases diameter of jugular veins (increases cephalad edema)
moves regurgitated material into pharynx
what parts of the patients anatomy should remain in neutral longitudinal alignment during lithotomy positioning?
head, neck, thorax should remain in neutral longitudinal alignment
what should be avoided when using the kidney rest for lateral decubitus positioning?
do not compress abdominal contents with the kidney rest
